rust: helpers: Add bindings/wrappers for dma_resv

This is just for basic usage in the DRM shmem abstractions for implied
locking, not intended as a full DMA Reservation abstraction yet.

Signed-off-by: Asahi Lina <lina@asahilina.net>

rust/bindings/bindings_helper.h

@@ -16,6 +16,7 @@
 #include <linux/blk_types.h>
 #include <linux/blkdev.h>
 #include <linux/cred.h>
+#include <linux/dma-resv.h>
 #include <linux/device/faux.h>
 #include <linux/errname.h>
 #include <linux/ethtool.h>

rust/helpers/dma-resv.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/dma-resv.h>
+
+int rust_helper_dma_resv_lock(struct dma_resv *obj, struct ww_acquire_ctx *ctx)
+{
+	return dma_resv_lock(obj, ctx);
+}
+
+void rust_helper_dma_resv_unlock(struct dma_resv *obj)
+{
+	dma_resv_unlock(obj);
+}

rust/helpers/helpers.c

@@ -11,6 +11,9 @@
 #include "bug.c"
 #include "build_assert.c"
 #include "build_bug.c"
+#ifdef CONFIG_DMA_SHARED_BUFFER
+#include "dma-resv.c"
+#endif
 #include "device.c"
 #include "drm/drm.c"
 #include "err.c"